Reducing energy losses in rotating electrical machines is a key contributor in enhancing conversion efficiency for countless applications. The maintenance requirements of rotating equipment also presents a challenge when designing, operating and maintaining power transmission drivetrains.
With the world now focusing on preserving critical resources and reducing emissions, there is a growing demand in many industries for electrical equipment that overcomes these challenges, achieving high efficiency with compact layout and simplified drivetrains. A viable solution in multiple fields is offered by permanent magnet technology, the focus of a new strategic initiative by leading Italian manufacturer of motors and generators, Marelli Motori.
Hydroelectric plant with multiple Marelli Motori alternators in operation
The peak for electromechanical efficiency
Permanent magnet technology allows the best electromechanical conversion efficiency in rotating equipment today. Key to this efficiency is the generation of the permanent magnetic field by the magnets themselves, instead of relying on electromagnetic coils as in traditional rotating equipment.
Moreover, the large flexibility in the number of poles and the torque/speed curves that are characteristic of permanent magnets open to a broader range of machine operating speeds. This allows for example for a direct drive layout in low revolutions applications, eliminating the need for a mechanical gearbox and simplifying the design, operation and maintenance of the equipment.
When compared to more traditional alternatives, these benefits can ensure the return on investment for permanent magnets is many times faster than the operating life.
“We are committed to developing permanent magnet technology, which we believe will be supported by double-digit growth in all major applications in coming years. Marelli Motori is well-positioned to take advantage of this growing market, thanks to the expertise already achieved during several projects in the past decade, as well as the ongoing efforts of our R&D department to find new solutions to address additional market opportunities" says Marco Cavallero, Sales & Marketing Director, Marelli Motori.
Permanent magnets are typically located in the rotor, where the excitation poles or induction cages would be found in conventional rotating equipment. The remaining parts, including stator, frames, and connections, etc., remain mostly unchanged.
Cross-section comparison between IPM and asynchronous machines
A master of rotating electrical equipment
For more than 125 years, Marelli Motori has manufactured rotating electrical equipment from TEFC induction motors, including for use in explosive atmospheres, to large alternators for hydroelectric and cogeneration plants, propulsion motors for thrusters and marine applications, and enhanced aftersales services for the wind power industry.
Wind turbine layout showing gearbox and electric generator
In addition to its broad portfolio of series synchronous and asynchronous motors and generators, the company offers customized design-to-order (DTO) machines for the most demanding applications. In total, this Italian powerhouse, part of British industrial and engineering group, Langley Holdings, delivers more than 70,000 machines and more than 6GW of installed power each year, including thousands of permanent magnet machines in recent years.
“Our state-of-the-art simulation and calculation tools, developed by our in-house R&D teams and executed by our first-class operations divisions, allows us to develop and certify almost all products available in our portfolio as DTO in a permanent magnet version,” says Andrea Casella, CTO of the company.
“With the highest respect for confidentiality and intellectual property, we are pleased to make available our manufacturing workshop and relevant technological assets to all market players looking for a best-in-class industrializer and producer of their own design machines in Italy” concludes Marco Cavallero.
Marelli Motori propulsion motors for marine vessels mounted on board
About Marelli Motori
Marelli Motori is a leading manufacturer of electric motors and generators. Founded in northern Italy in 1891, the company enjoys worldwide brand recognition in the marine, oil & gas, power generation, co-generation, hydro, and other industrial sectors.
Marelli Motori employs around 500 people and operates an extensive manufacturing facility in Italy with own subsidiaries in the United States, Germany, South Africa and Malaysia and has an extended sales, distribution, and service network across four continents, supplying its technologically advanced products in more than 120 countries.
On 24 May 2019, Marelli Motori was acquired by Langley Holdings plc, the British engineering and industrial group.